Download or read book Search for Higgs Boson Pair Production in the bb Decay Channel written by Luca Cadamuro and published by Springer. This book was released on 2018-12-06 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents innovative contributions to the CMS experiment in the new trigger system for the restart of the LHC collisions in Run II, as well as original analysis methods and important results that led to official publications of the Collaboration. The author's novel reconstruction algorithms, deployed on the Field-Programmable Gate Arrays of the new CMS trigger architecture, have brought a gain of over a factor 2 in efficiency for the identification of tau leptons, with a very significant impact on important H boson measurements, such as its decays to tau lepton pairs and the search for H boson pair production. He also describes a novel analysis of HH → bb tautau, a high priority physics topic in a difficult channel. The original strategy, optimisation of event categories, and the control of the background have made the result one of the most sensitive concerning the self-coupling of the Higgs boson among all possible channels at the LHC.

Download or read book Searches for Higgs Boson Pair Production in the Hh u2192 bb WW bb Bbbb Channels with the ATLAS Detector written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Searches for both resonant and nonresonant Higgs boson pair production are performed in the hh → bb??, ??WW* final states using 20.3 fb-1 of pp collision data at a center-of-mass energy of 8 TeV recorded with the ATLAS detector at the Large Hadron Collider. No evidence of their production is observed and 95% confidence-level upper limits on the production cross sections are set. These results are then combined with the published results of the hh → ??bb, bbbb analyses. An upper limit of 0.69 (0.47) pb on the nonresonant hh production is observed (expected), corresponding to 70 (48) times the SM gg → hh cross section. For production via narrow resonances, cross-section limits of hh production from a heavy Higgs boson decay are set as a function of the heavy Higgs boson mass. The observed (expected) limits range from 2.1 (1.1) pb at 260 GeV to 0.011 (0.018) pb at 1000 GeV. In addition, these results are interpreted in the context of two simplified scenarios of the Minimal Supersymmetric Standard Model.

Download or read book Search for Resonant Higgs Boson Pair Production in the Semi leptonic Bb WW Decay Channel with the ATLAS Detector at the Large Hadron Collider written by Nurfikri Bin Norjoharuddeen and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for Resonant Higgs Boson Pair Production in the Bb WW Decay Channel in the Boosted 1 lepton Final State Using the Full Run 2 ATLAS Dataset written by Kira Abeling and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite the great success of the Standard Model of Particle Physics in explaining physics phenomena over a wide range of energy scales, many open questions remain and it is known that this model of nature is incomplete. The Higgs boson as the most recent discovered particle has completed the Standard Model. With its coupling to mass, it is an excellent candidate to shed light on physics beyond the Standard Model. This thesis presents the search for resonant Higgs boson pair (HH) production as well as resonant production of a Higgs boson in association with another additional scalar particle...

Download or read book Search for the Higgs Boson in the Vector Boson Fusion Channel at the ATLAS Detector written by Eric Ouellette and published by Springer. This book was released on 2015-01-20 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Thesis describes the first measurement of, and constraints on, Higgs boson production in the vector boson fusion mode, where the Higgs decays to b quarks (the most common decay channel), at the LHC. The vector boson fusion mode, in which the Higgs is produced simultaneously with a pair of quark jets, provides an unparalleled opportunity to study the detailed properties of the Higgs, including the possibility of parity and CP violation, as well as its couplings and mass. It thus opens up this new field of study for precision investigation as the LHC increases in energy and intensity, leading the way to this new and exciting arena of precision Higgs research.

Download or read book Higgs Boson Production with a Top Quark Pair in the Diphoton Channel Double Higgs Production in the Bb diphoton Channel and Inner Tracker Upgrade with the Atlas Detector at the Large Hadron Collider written by Alex Zeng Wang and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the discovery of the Higgs boson in 2012, the diphoton ([gamma][gamma]) decay channel of the Higgs boson has been one of the most potent channels due to the contrast between the smoothly falling background and sharply peaked signal in the diphoton invariant mass. In 2018, with up to 80 fb-1 of data at [square root]s = 13 TeV, ATLAS observed Higgs boson production in association with a pair of top quarks (ttH) with a significance of 5.8 [sigma] by combining measurements in the [gamma][gamma], bb, ZZ, and multi-lepton Higgs decay channels. The ttH production cross-section was measured to be 670 [plus or minus] 90 (stat) +110 -100 (syst) fb. The diphoton channel was one of the main contributors to this result, alone providing a significance of 4.1 [sigma]. With 140 fb-1, a search for non-resonant Higgs pair production in the bb[gamma][gamma] final state was performed. No significant signal was observed and upper limits at 95% confidence level were set. The observed limit on the SM cross-section was 130 fb, or 4.2 times the predicted value. The observed Higgs trilinear coupling modifier was constrained to be between [-1.5, 6.7]. Both the ttH (H [rightwards arrow] [gamma][gamma]) and HH bb[gamma][gamma] analyses will benefit tremendously from the increased statistics expected from the High-Luminosity LHC (HL-LHC). To ensure the continued efficiency of the detector in the harsh HL-LHC environment, ATLAS will install a new Inner Tracker (ITk) consisting of silicon pixel sensors in its innermost layer. At SLAC National Accelerator Laboratory, a variety of electrical tests are performed for the construction of a prototype integrated pixel system, in order to provide early feedback and validation of the ITk design.

Download or read book Search for tt H Production in the H bb Decay Channel written by Marcel Rieger and published by Springer Nature. This book was released on 2021-02-25 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1964, a mechanism explaining the origin of particle masses was proposed by Robert Brout, François Englert, and Peter W. Higgs. 48 years later, in 2012, the so-called Higgs boson was discovered in proton-proton collisions recorded by experiments at the LHC. Since then, its ability to interact with quarks remained experimentally unconfirmed. This book presents a search for Higgs bosons produced in association with top quarks tt̄H in data recorded with the CMS detector in 2016. It focuses on Higgs boson decays into bottom quarks H → bb̅ and top quark pair decays involving at least one lepton. In this analysis, a multiclass classification approach using deep learning techniques was applied for the first time. In light of the dominant background contribution from tt̄ production, the developed method proved to achieve superior sensitivity with respect to existing techniques. In combination with searches in different decay channels, the presented work contributed to the first observations of tt̄H production and H → bb̅ decays.

Download or read book Searches for Higgs Boson Pair Production in the math Display written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Searches for both resonant and nonresonant Higgs boson pair production are performed in the hh → bb[tau][tau], [gamma][gamma]WW* final states using 20.3 fb-1 of pp collision data at a center-of-mass energy of 8 TeV recorded with the ATLAS detector at the Large Hadron Collider. No evidence of their production is observed and 95% confidence-level upper limits on the production cross sections are set. These results are then combined with the published results of the hh → [gamma][gamma]bb, bbbb analyses. An upper limit of 0.69 (0.47) pb on the nonresonant hh production is observed (expected), corresponding to 70 (48) times the SM gg → hh cross section. For production via narrow resonances, cross-section limits of hh production from a heavy Higgs boson decay are set as a function of the heavy Higgs boson mass. The observed (expected) limits range from 2.1 (1.1) pb at 260 GeV to 0.011 (0.018) pb at 1000 GeV. In addition, these results are interpreted in the context of two simplified scenarios of the Minimal Supersymmetric Standard Model.

Download or read book Search for Higgs Leptoquarks and Exotics at Tevatron written by Song Ming Wang and published by . This book was released on 2004 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of Higgs Boson Production and Properties in the WW Decay Channel with Leptonic Final States written by and published by . This book was released on 2014 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for the standard model Higgs boson decaying to a W-boson pair at the LHC is reported. The event sample corresponds to an integrated luminosity of 4.9 and 19.4 inverse femtobarns collected with the CMS detector in pp collisions at √s = 7 and 8 TeV, respectively. The Higgs boson candidates are selected in events with two or three charged leptons. An excess of events above background is observed, consistent with the expectation from the standard model Higgs boson with a mass of around 125 GeV. The probability to observe an excess equal or larger than the one seen, under the background-only hypothesis, corresponds to a significance of 4.3 standard deviations for mH = 125.6 GeV. The observed signal cross section times the branching fraction to WW for mH = 125.6 GeV is 0.72+0.20-0.18 times the standard model expectation. The spin-parity JP=0+ hypothesis is favored against a narrow resonance with JP=2+ or JP=0- that decays to a W-boson pair. Lastly, this result provides strong evidence for a Higgs-like boson decaying to a W-boson pair.

Download or read book Search for a Higgs Boson in the Decay Channel H to ZZ to q Qbar ell L in pp Collisions at sqrt s written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for the standard model Higgs boson decaying into two Z bosons with subsequent decay into a final state containing two quark jets and two leptons, H to ZZ(*) to q q-bar l-l+ is presented. Results are based on data corresponding to an integrated luminosity of 4.6 inverse femtobarns of proton-proton collisions at sqrt(s)=7 TeV, collected with the CMS detector at the LHC. In order to discriminate between signal and background events, kinematic and topological quantities, including the angular spin correlations of the decay products, are employed. Events are further classified according to the probability of the jets to originate from quarks of light or heavy flavor or from gluons. No evidence for the Higgs boson is found, and upper limits on its production cross section are determined for a Higgs boson of mass between 130 and 600 GeV.

Download or read book Search for Higgs Boson Pair Production in the Gamma Gamma B b over bar Final State Using Pp Collision Data at Root S written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for Higgs boson pair production \(pp \rightarrow hh\) is performed with 19.5 fb\(^{-1}\) of proton-proton collision data at \(\sqrt{s}=8\) TeV, which were recorded by the ATLAS detector at the Large Hadron Collider in 2012. The decay products of each Higgs boson are reconstructed as a high-momentum \(b\bar{b}\) system with either a pair of small-radius jets or a single large-radius jet, the latter exploiting jet substructure techniques and associated b-tagged track-jets. No evidence for resonant or non-resonant Higgs boson pair production is observed. The data are interpreted in the context of the Randall-Sundrum model with a warped extra dimension as well as the two-Higgs-doublet model. An upper limit on the cross-section for \(pp\rightarrow G^{*}_{\mathrm {KK}} \rightarrow hh \rightarrow b\bar{b}b\bar{b} \) of 3.2 (2.3) fb is set for a Kaluza-Klein graviton \(G^{*}_{\mathrm {KK}}\) mass of 1.0 (1.5) TeV, at the 95 % confidence level. The search for non-resonant Standard Model hh production sets an observed 95 % confidence level upper limit on the production cross-section \(\sigma (pp \rightarrow hh \rightarrow b\bar{b}b\bar{b})\) of 202 fb, compared to a Standard Model prediction of \(\sigma (pp \rightarrow hh \rightarrow b\bar{b}b\bar{b}) = 3.6 \pm 0.5\) fb.

Download or read book Search for Higgs Boson Pair Production in the bbll ETmiss final state with the ATLAS detector at s written by Benjamin Rottler and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for Higgs Boson Pair production in the Bb Final State Using Proton proton Collisions at s written by Zhiyuan Li and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for the Standard Model Higgs Boson in the Z Gamma Channel written by Kevin Singh and published by . This book was released on 2013 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Higgs decay into a photon and a Z boson, with the Z boson decaying into an electron-positron pair (electron channel) or muon-antimuon pair (muon channel), allows for accurate reconstructions of the Higgs boson mass and measurement of the Higgs to Z-[gamma] coupling. We explore selection criteria for the photon and the two leptons and provide preliminary observed and expected limits for the Higgs boson production cross section in the mass range from 120 GeV to 150 GeV. The data used in this analysis was collected with the CMS detector and corresponds to 5 fb- 1 and 19 fb-1 at center-of-mass energies of 7 TeV and 8 TeV, respectively.

Download or read book Search for Higgs Boson Pair Production in the Two Bottom Quarks Plus Two Photons Final State in Pp Collisions at square Root s written by [Study Group] ATLAS Collaboration CERN and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Particle Physics Reference Library written by Herwig Schopper and published by Springer Nature. This book was released on 2020 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first open access volume of the handbook series contains articles on the standard model of particle physics, both from the theoretical and experimental perspective. It also covers related topics, such as heavy-ion physics, neutrino physics and searches for new physics beyond the standard model. A joint CERN-Springer initiative, the "Particle Physics Reference Library" provides revised and updated contributions based on previously published material in the well-known Landolt-Boernstein series on particle physics, accelerators and detectors (volumes 21A, B1,B2,C), which took stock of the field approximately one decade ago. Central to this new initiative is publication under full open access